The Preparation And Properties Of Bacterial Cellulose/polyaniline Nanocomposite Membrane

Polyaniline has become one of the most widely studied conducting polymersidue to its diverse structures, high conductivity, good environmental stability and low cost. But the poor solubility and mechanical properties limit its processing and application. So many researchers focus on how to improve them.Bacterial cellulose (BC) is a kind of biological cellulose synthesized by microbial fermentation. There are many active hydroxyl on surface, so it has a high reactivity and a good template effect that can control the morphology of the composite during the reaction.BC can act as a substrate due to its good mechanical properties, flexibility and machinability and through compositing functional materials we can get multifunctional composite membrane with great properties.First, the work started from researching the best way to synthesis BC/PANI conductive composite membrane, and then focused on exploring the effect on the properties of conductive when change reaction conditions. After that, investigation was taken on the properties characterization when we changed the type of doping acid. The detail researches are as follows:1. Before the composition, BC was processed in three ways:squeezing to remove the free water, freeze-dried and beating. And the BC/PANI composite membranes were prepared by physical blend methods and in suit polymerization. The best composite method was determined by morpgology analysis, FT-IR, electrical conductivity and mechanical properties. The results revealed that by in suit polymerization with a squeezed BC, the prepared BC/PANI membrane has high conductivity (0.19S/cm) and excellent mechanical properties.2. Based on the determined composite method, different monomer concentration, the ratio of monomer and oxidant, doping acid concentration and the reaction temperature was controlled separately to prepare the BC/PANI membranes and explored an optimum reaction conditions. The mechanism and influence were discussed through the characterization. The conductivity can reach0.76S/cm when the concentration of monomer is0.20mol/L, the molar ratio of monomer and oxidizer is1:1, the concentration of doping acid is1.0mol/L and the temperature is0℃.3. By using the determined composite method and the optimum reaction conditions, the differences of properties were studied when changed the type of doping acid.The conductivity of BC/PANI composite membrane can reach1.18S/cm when doped by the mixed acid HC1+SSA with the molar ratio of25:1. The conductivity of the conductive composite membrane showed a trend of decline after an increase with the increase of torsion Angle and tensile stress. In the range of40℃to60℃, the conductivity of composite membranes show a linear relation as temperature increase and decrease. BC/PANI membranes doped with different acid show different cooling amplitude through the infrared thermal imager test, which can be designed and applied in infrared stealth field.